import java.util.*;
import java.sql.*;
import static java.lang.Math.*;

/**
 * Created with IntelliJ IDEA.
 * Description:
 */
public class Main {

    public static void main(String[] args) {
        double x = 30;
        double y = 40;
//        double result = Math.sqrt(Math.pow(x,2) + Math.pow(y,2));
        double result = sqrt(pow(x,2) + pow(y,2));

        System.out.println(result);
    }

    public static void main1(String[] args) {
//        Date date = new Date();
        java.util.Date date = new java.util.Date();
        //得到时间戳
        System.out.println(date.getTime());
    }
}
